Nonparametric optimal designs for degradation tests.

This paper discusses the optimal design of a degradation test within the nonparametric framework by assuming the underlying process to be an empirical Lévy process with heterogeneity. The optimization of the experiment relies on the design variables including the sample size, the measurement frequency and total operation time. It is necessary to investigate the effect of the design variables on the estimation of first passage time (FPT). Subject to total experimental cost not exceeding a pre-specified budget, the values of design variables are determined such that the bootstrap mean square error of the 100 p th percentile of the FPT distribution is minimized.